Mirage IV

The Dassault Mirage IV is a supersonic strategic bomber and reconnaissance aircraft produced by the French manufacturer Dassault Aviation. It entered service with the French Air Force in October 1964 and was, until 1971, the sole nuclear delivery vehicle of the Force de frappe. It was withdrawn from the nuclear mission in 1996 and from operational service in 2005.

Development

Development began in 1956 as part of the French nuclear programme. In May 1956, the Guy Mollet government drew up a specification for a supersonic bomber capable of in-flight refuelling, able to carry a three-tonne, 5.2 m long nuclear bomb over 2,000 km. The final specifications were approved on 20 March 1957. Sud Aviation proposed the Super Vautour and Nord Aviation another solution; Dassault won in April 1957, its Mirage III-derived proposal being judged cheaper and simpler to develop. The Mirage IV 01 prototype, built in 18 months at Saint-Cloud, made its first flight on 17 June 1959 in the hands of Roland Glavany. On 19 September 1960, René Bigand raised the world speed record over a 1,000 km closed circuit to 1,822 km/h, then to 1,972 km/h over 500 km on 23 September. An enlarged project, the J75-powered Mirage IVB, was cancelled in July 1959 on cost grounds. An order for 50 Mirage IVAs was placed on 4 April 1960; the first production aircraft flew on 7 December 1963. In total, 62 examples were built and delivered between 1964 and 1968. Sud Aviation supplied the wings and rear fuselage, Breguet the fin. Export variants, including the Rolls-Royce Spey-powered Mirage IV* (or IVS) proposed jointly with BAC to the RAF in July 1965, were not selected; the F-111K was preferred. Australia also passed it over in favour of the F-111C.

Design

The aircraft retains the tailless delta wing and fin of the Mirage III, but with a thickness/chord ratio of 3.8% at the root and 3.2% at the tip. It is powered by two SNECMA Atar turbojets fed by intakes with movable half-cone centrebodies known as "souris" (mice), and limited to Mach 2.2 for thermal reasons. Internal fuel capacity is 14,000 litres, held in integral tanks; a refuelling probe is built into the nose. The two-man crew, pilot and navigator, sits in tandem under two separate canopies. A bombing and navigation radar is housed in a ventral radome between the intakes; most of the avionics come from Thomson-CSF, SFENA and Dassault, the Marconi AD.2300 Doppler radar being one of the few foreign items.

Armament

The Mirage IVA carries in a ventral recess a 60 kt AN-11 or AN-22 nuclear bomb, or up to 16 conventional bombs of 454 kg. Four underwing pylons take 2,500-litre tanks on the inboard stations and ECM or chaff/flare dispenser pods on the outboard stations, including the Barax NG jammer and the BOZ dispenser. No gun was ever fitted. From 1972, twelve aircraft received the CT52 reconnaissance pod; in the 1980s, eighteen aircraft were fitted with a ventral pylon for the ASMP nuclear missile.

Operational History

Deliveries began in February 1964 and the first squadron was declared operational on 1 October. The force reached nine squadrons of four aircraft spread over nine bases, including 1/91 "Gascogne" at Mont-de-Marsan and 2/93 "Cévennes" at Orange. Thirty-six aircraft were on alert, twelve of them airborne, complemented by 26 in reserve. Fourteen Boeing C-135F tankers were acquired, the Mirage IVs often operating in pairs with "buddy" refuelling. The targets were major Soviet cities and bases, including Moscow and Murmansk. In ten years, the fleet accumulated more than 200,000 flight hours and 40,000 refuellings. The initial high-altitude profile at Mach 1.85 was abandoned in the late 1960s in favour of low-altitude penetration. The first operational use of the CT52 took place over Chad in September 1974. In the reconnaissance role, the Mirage IVP operated over Bosnia, Iraq, Kosovo and Afghanistan. No export customer was found.

Variants

• Mirage IV 01: 20 m long experimental prototype, first flown on 17 June 1959, used for sustained supersonic cruise trials.
• Mirage IVB: Enlarged project with J75 engines, 120 m² wing and Mach 2.4, cancelled in July 1959.
• Mirage IVA: Production version of 62 examples, 77.9 m² wing, carrying an AN-11 or AN-22 nuclear bomb.
• Mirage IVR: Twelve IVAs modified from 1972 to carry the CT52 reconnaissance pod in the ventral recess.
• Mirage IVP: Eighteen aircraft modernised under the July 1984 contract for the ASMP missile, first flight on 12 October 1982 and return to service on 1 May 1986.